The present invention relates to a color image compression method and apparatus.
Color image scanners with built-in compression schemes have been well known in the prior art (as long as there have been facsimile machines). However, the purpose for that compression is to reduce the bandwidth required in a transmission medium. That transmission medium is invariably a telephone line and at the other end is another facsimile machine.
Color facsimile systems are known (such as one manufactured by Star Signal of Campbell, California). That system has a color scanner, a PC computer with compression board(s) plugged in, and a color printer for output. Full color images are transmitted from the scanner to the PC where the image is passed to a color compression board and then transmitted down a telephone line. Incoming messages are received by the PC, decompressed by the board(s) and sent to the printer.
The limiting factor in modern day scanners is the bandwidth of the link, as indicated above. Typically scanners are able to produce data up to 4-5 Megabytes per second, while the transmission link (that from the transmit line to the PC) is only capable of 0.5 Megabytes per second.
It would be desirable, therefore, to provide an improved color image compression apparatus and method.